1. Field of the Invention
The present invention relates to an apparatus for transporting a sheet, which is utilized, for example, in a copying apparatus.
2. Description of the Related Art
A sheet transporting apparatus is utilized in various kinds of apparatuses such as a copying apparatus, a printing apparatus etc., in which copying sheets etc. are to be transported sequentially and speedily one after another.
Such a transporting apparatus includes a plurality of transporting rollers.
In case that such a sheet transporting apparatus is utilized in a copying apparatus having a plurality of sheet supplying trays with the function of both-side-copy operation, the transporting path for the copying sheet is made rather complicated and long. Accordingly, in this case, a large number of the transporting rollers are required to deal with the complicated and long path.
In this type of sheet transporting apparatus, some transporting rollers are not coupled to other transporting rollers and are rotated independently from each other, so that the sequential transportation of the sheet through the long and complicated path is enabled by controlling the driving condition of each transporting roller in a prescribed manner, in accordance with the position of the transported copying sheet and the selected tray.
In this type of sheet transporting apparatus, since such a driving control manner that some transporting rollers are rotated while other transporting rollers are stopped, is possible, the copying sheet can be transported to some midway of the transporting path before the transportation of the previous copying sheet is completed, with a benefit of increasing the total copying speed.
In the above mentioned sheet transporting apparatus, when an abnormal condition of the transported sheet occurs, for example, when the copying sheet is jammed in the transporting path, the driving of the transporting rollers are stopped. At this moment, since the jammed sheet is not necessarily positioned at a place where the jammed sheet can be removed by an operator, the transporting rollers are manually rotated by the operator, so that the jammed sheet is moved to some other position of the transporting path where the jammed sheet can be removed by the operator.
In this removing operation, however, since the plurality of rollers are not coupled to each other, it is necessary to rotate different rollers one after another until the jammed sheet reaches the desired position for removing, resulting in a time consuming and troublesome removing operation.